In one class of valves, the valve member is intended to move to a particular position when acted upon by a predetermined force. For instance, in the case of a pressure relief valve, the valve member would be biased toward a closed position, but could open when fluid pressure acting on an opening hydraulic surface exceeds some predetermined valve opening pressure. In another example, a pressure reducing valve moves to an open position when pressure on the low pressure side of the valve drops below some predetermined valve opening pressure. Because these valves must often be comprised of several components, and each of those components must have a realistic manufacturing tolerance, mass producing valves with consistent valve opening pressures can be problematic. Some of these problems can be attributed to difficulty in setting a desired valve operation parameter, such as valve opening pressure, when stacked geometrical or other tolerances result in a plurality of valves all with slightly differently shaped or strengthened components. Variations on the desired valve operation parameter can often be a strong function of variability among component tolerances, and the problem is often compounded by stacked tolerances from multiple components.
The present invention is directed to these and other problems associated with mass producing valves with consistent and/or predictable valve operating parameters.